TIA Patients Research Articles

Abstract T MP31: Imaging of 68Ga-PRGD2 PET/CT for αvβ3-integrin in Severe Intracranial Atherosclerotic Stenosis Patients

Background: Angiogenesis has been demonstrated in acute cerebral infarct lesion. Intracranial atherosclerotic stenosis(ICAS)is usually associated with chronic cerebral ischemia. It is uncertain whether angiogenesis exist in such circumstance. αvβ3-integrin is expressed by angiogenic endothelial cells and serve as a biomarker of angiogenesis. 68Ga-PRGD2 which is a PET tracer specifically binding to toαvβ3-integrin was used for imaging angiogenesis. Objective: To evaluate the status of angiogenesis in patients with severe ICAS. Method: For the pilot study, patients with unilateral ICAS were recruited. 68Ga-PRGD2 PET/CT, 13N-Amonia PET/CT and 18F-FDG PET/CT scans were performed. The procedures were done at least 45 days after index ischemic event in symptomatic ICAS patients. The PET images were evaluated by semi-quantitative analysis. Peak standardized uptake value (pSUV)were calculated. pSUV was compared between hemisphere supplied by ICAS and opposite side. Correlation analysis were applied between pSUV of 68Ga-PRGD2, and 13N-Amonia. Informed consent were obtained. Results: Nine patients were studied, 6 with symptomatic (45 days to 19 years post ischemic event) and 3 asymptomatic ICAS. Among them, there were 3 ICA occlusion, 3 MCA occlusion and 3 MCA stenosis (unilateral ≥70%). 68Ga-PRGD PET/CT showed significantly higher pSUV in lesion sides (0.22 vs 0.08, P<0.02 ). There are no significant difference between SUV of 13N-Amonia (3.59 vs 3.90,p=0.489) and 18F-FDG(12.42 vs 13.86,p=0.34). pSUV of 13N-Amonia in lesion sides significantly correlates with pSUV of 68Ga-PRGD2 (r=-0.77, P=0.015). Conclusion: 68Ga -PRGD2 uptake was observed beyond acute phase in patient with severe ICAS. Chronic cerebral ischemic might induce angiogenesis in addition to acute ischemic event. Further study to explore the mechanism was warranted. Fig.1 Images of a TIA patient 45 days after onset. C. Obvious uptake of 68Ga -PRGD2 (arrow). D. Lightly low uptake of 18F-FDG .

Abstract T P276: Transient Ischemic Attack Clinic Drives Superior Patient Outcomes While Reducing Cost

It is estimated that 40% of all individuals that experience a TIA will ultimately suffer a stroke. As many as 50% of these patients will have a stroke within one week post TIA. Given the short time interval between TIA symptomology and stroke onset, immediate treatment is warranted. Historically treatment of TIA patients has taken place in emergency rooms and as hospital inpatients. A TIA clinic was established in 2011 as an alternative option to traditional TIA treatment. This clinic was designed to expedite diagnosis and treatment while reducing cost. Utilizing the ABCD2 tool, emergency department clinicians, PCPs and ophthalmologists referred low risk patients to the clinic. Clinic patients were scheduled to be seen in the clinic within 24-48 hours. All testing, stroke/TIA education, neurological consultation and secondary treatment plan were completed during the clinic visit. To date, the clinic has evaluated 137 patients. There have been no reports of stroke 90-days post clinic visit. Stroke rates post TIA are estimated to be as high as 17% after 3 months. This data supports the TIA clinic’s success in secondary stroke prevention. Patients seen in the clinic reported high satisfaction scores with the clinic and the care they received. It was initially hypothesized that the TIA clinic would provide care in a more cost effective way. A cost analysis was performed comparing TIA clinic costs and the cost of treating patients admitted to the hospital. Using fiscal year 2014 data, the average cost for treating a patient in the clinic was $423. The average cost for admitting a patient to the hospital was $1,464 per patient. The TIA clinic has shown that patients can receive timely treatment in a setting that produces the highest clinical outcomes, maintains patient satisfaction and reduces cost by 70%.

Abstract W P301: A Neurology/Emergency Medicine Co-Management Protocol for the Observation Management of Transient Ischemic Attack

Background: TIAs are potentially unstable conditions that frequently precede acute ischemic stroke (IS). An evaluation for thromboembolic source and risk is indicated; unfortunately, diagnostic resources for this work up are not immediately available in the Emergency Department (ED). In response to logistic difficulties arranging timely outpatient workup as well as inappropriately long lengths of stay (LOS) on the inpatient Neurology service, we developed a co-management protocol in the ED-based Clinical Decision Unit (CDU). We aimed to evaluate the quality of this model in terms of efficiency and prevention of stroke at 30 days. Methods: Eligible patients were those with resolved or minimal symptoms, hemodynamic stability, and no known source of emboli (artificial valve, endocarditis, or atrial fibrillation requiring anticoagulation). The protocol consisted of ongoing ED management with Neurology consultation and determination of the diagnostic evaluation, which could include MRI, cardiac echo, and carotid ultrasound/transcranial Doppler. Patients with IS on MRI or carotid stenosis were admitted; the remainder discharged on antiplatelet medication and Neurology follow-up. Using a retrospective case control design, we reviewed records of consecutive patients managed in the CDU TIA protocol in the first 6 months of 2014. Controls consisted of 100 TIA patients (discharged without confirmed CVA) managed on the Neurology service prior to the implementation of the CDU TIA protocol. Outcomes included LOS and 30 day readmission rate for acute IS. Results: There were 127 CDU patients and 100 controls in the sample. After CDU evaluation, 31 patients required further inpatient admission (24%, 95%CI 17-33%) due to demonstration of acute IS or severe carotid stenosis. The average CDU LOS was 12.2 (SD 6.9) hours compared with 42 (SD 35.3) hours in the historical controls (p<0.001 per t-test for unequal variances). No patients discharged from the CDU TIA protocol returned within 30 days with IS (0%, 97.5%CI 0-2.9%). Conclusion: An ED/Neurology co-managed CDU-based observation protocol for patients with TIA greatly reduced LOS and variability, with no detected rate of IS readmissions within 30 days of discharge.

Cervical Artery Dissection in Young Adults in the Stroke in Young Fabry Patients (sifap1) Study

Background: Patients with carotid artery dissection (CAD) have been reported to have different vascular risk factor profiles and clinical outcomes to those with vertebral artery dissection (VAD). However, there are limited data from recent, large international studies comparing risk factors and clinical features in patients with cervical artery dissection (CeAD) with other TIA or ischemic stroke (IS) patients of similar age and sex. Methods: We analysed demographic, clinical and risk factor profiles in TIA and IS patients ≤55 years of age with and without CeAD in the large European, multi-centre, Stroke In young FAbry Patients 1 (sifap1) study. Patients were further categorised according to age (younger: 18-44 years; middle-aged: 45-55 years), sex, and site of dissection. Results: Data on the presence of dissection were available in 4,208 TIA and IS patients of whom 439 (10.4%) had CeAD: 196 (50.1%) had CAD, 195 (49.9%) had VAD, and 48 had multiple artery dissections or no information regarding the dissected artery. The prevalence of CAD was higher in women than in men (5.9 vs. 3.8%, p < 0.01), whereas the prevalence of VAD was similar in women and men (4.6 vs. 4.7%, n.s.). Patients with VAD were younger than patients with CAD (median = 41 years (IQR = 35-47 years) versus median = 45 years (IQR = 39-49 years); p < 0.01). At stroke onset, about twice as many patients with either CAD (54.0 vs. 23.1%, p < 0.001) or VAD (63.4 vs. 36.6%, p < 0.001) had headache than patients without CeAD and stroke in the anterior or posterior circulation, respectively. Compared to patients without CeAD, hypertension, concomitant cardiovascular diseases and a patent foramen ovale were significantly less prevalent in both CAD and VAD patients, whereas tobacco smoking, physical inactivity, obesity and a family history of cerebrovascular diseases were found less frequently in CAD patients, but not in VAD patients. A history of migraine was observed at a similar frequency in patients with CAD (31%), VAD (27.8%) and in those without CeAD (25.8%). Conclusions: We identified clinical features and risk factor profiles that are specific to young patients with CeAD, and to subgroups with either CAD or VAD compared to patients without CeAD. Therefore, our data support the concept that certain vascular risk factors differentially affect the risk of CAD and VAD.

Is nonadmission-based care for TIA patients cost-effective?: A microcosting study.

We previously demonstrated the safety and effectiveness of a nonadmission-based model for TIA care (Monash TIA Triaging Treatment [M3T]). In this microcosting study, we used a pre-post cohort design with multivariable uncertainty analyses to compare actual resource utilization costs between M3T (years 2004-2007) and the previous admission-based model (2003). Average total episode costs per patient were significantly less for M3T (Australian dollars [AUD] 1,927.00, 95% confidence interval [CI] AUD 1,829.00-1,037.00) compared with the admission-based model (AUD 4,841.00, 95% CI AUD 4,178.00-5,590.00). Nonadmission care in M3T was substantially cost-saving with a median 3 (95% uncertainty interval 0.7-6.0) additional strokes averted per 100 patients treated, based on an observed 90-day stroke rate of 1.50% (95% CI 0.73%-3.05%) and 4.67% (95% CI 2.28%-9.32%) in the admission-based model.

Metabolomics predicts stroke recurrence after transient ischemic attack.

To discover, by using metabolomics, novel candidate biomarkers for stroke recurrence (SR) with a higher prediction power than present ones. Metabolomic analysis was performed by liquid chromatography coupled to mass spectrometry in plasma samples from an initial cohort of 131 TIA patients recruited <24 hours after the onset of symptoms. Pattern analysis and metabolomic profiling, performed by multivariate statistics, disclosed specific SR and large-artery atherosclerosis (LAA) biomarkers. The use of these methods in an independent cohort (162 subjects) confirmed the results obtained in the first cohort. Metabolomics analyses could predict SR using pattern recognition methods. Low concentrations of a specific lysophosphatidylcholine (LysoPC[16:0]) were significantly associated with SR. Moreover, LysoPC(20:4) also arose as a potential SR biomarker, increasing the prediction power of age, blood pressure, clinical features, duration of symptoms, and diabetes scale (ABCD2) and LAA. Individuals who present early (<3 months) recurrence have a specific metabolomic pattern, differing from non-SR and late SR subjects. Finally, a potential LAA biomarker, LysoPC(22:6), was also described. The use of metabolomics in SR biomarker research improves the predictive power of conventional predictors such as ABCD2 and LAA. Moreover, pattern recognition methods allow us to discriminate not only SR patients but also early and late SR cases.

Stroke occurence in Germany - on the comparability of insurance data and registry-based data

This article presents epidemiological data regarding stroke frequency in Germany based on nationwide statutory health insurance data (Deutsche BKK) and aims to analyse them in the context of current research. The comparability of the most important resources of stroke frequency data - stroke registers, DRG data and insurance data - is initially discussed in order to assess the presented data adequately. The study cohort comes from a population of about 1 000 000 people insured with BKK and consists of all persons who were treated for a stroke in an acute care hospital in 2007 (n = 4,843). Data were subjected to statistical secondary analysis including uni- and bivariate statistics and t tests. Reference studies for the observation period include data from GEK and AOK health insurances, from quality assurances Hessen and Bayern, from the ADSR, and hospital DRG data. The different study types are compared regarding their inclusion/exclusion criteria and the resulting effects on reported prevalences. Different inclusion criteria and accordingly different operationalisations of "stroke" impede the comparability of existing German data resources regarding stroke. The inclusion of TIA, non-traumatic subdural haemorrhage (I62), and the frequency of unspecified strokes (I64) is especially inconsistent. In addition, recurrent strokes and the definition of first-ever strokes are treated differently. The study cohort reveals no major discrepancies regarding aetiological subgroups compared to previous results, only the percentage of women (60.3 %) seems exceptionally high. The gender effect is attributed to the BKK member structure, and especially the high proportion of women in the older age groups. Discussion of stroke frequency in Germany needs to take structural differences between study types into account. There are two vulnerable groups that tend to be underrepresented: TIA patients with a high risk of recurrent strokes, and high-risk patients who have already had a stroke and are care-dependent, which are often unspecifically coded. In the future, study designs should include the whole range of stroke coding, thus enabling differentiated analyses.

TIA triage in emergency department using acute MRI (TIA-TEAM): a feasibility and safety study.

Positive diffusion weighted imaging (DWI) on MRI is associated with increased recurrent stroke risk in TIA patients. Acute MRI aids in TIA risk stratification and diagnosis. To evaluate the feasibility and safety of TIA triage directly from the emergency department (ED) with acute MRI and neurological consultation. Consecutive ED TIA patients assessed by a neurologist underwent acute MRI/MRA of head/neck per protocol and were hospitalized if positive DWI, symptomatic vessel stenosis, or per clinical judgment. Stroke neurologist adjudicated the final TIA diagnosis as definite, possible, or not a cerebrovascular event. Stroke recurrence rates were calculated at 7, 90, 365 days and compared with predicted stroke rates derived from historical DWI and ABCD(2) score data. One hundred twenty-nine enrolled patients had a mean age of 69 years (± 17) and median ABCD(2) score of 3 (interquartile range [IQR] 3-4). During triage, 112 (87%) patients underwent acute MRI after a median of 16 h (IQR 10-23) from symptom onset. No patients experienced a recurrent event before imaging. Twenty-four (21%) had positive DWI and 8 (7%) had symptomatic vessel stenosis. Of the total cohort, 83 (64%) were discharged and 46 (36%) were hospitalized. By one-year follow-up, one patient in each group had experienced a stroke. Of 92 patients with MRI and index cerebrovascular event, recurrent stroke rates were 1.1% at 7 and 90 days. These were similar to predicted recurrence rates. TIA triage in the ED using a protocol with neurological consultation and acute MRI is feasible and safe. The majority of patients were discharged without hospitalization and rates of recurrent stroke were not higher than predicted.

Etiologic Classification of TIA and Minor Stroke by A-S-C-O and Causative Classification System as Compared to TOAST Reduces the Proportion of Patients Categorized as Cause Undetermined

Background: The assortment of patients based on the underlying pathophysiology is central to preventing recurrent stroke after a transient ischemic attack and minor stroke (TIA-MS). The causative classification of stroke (CCS) and the A-S-C-O (A for atherosclerosis, S for small vessel disease, C for Cardiac source, O for other cause) classification schemes have recently been developed. These systems have not been specifically applied to the TIA-MS population. We hypothesized that both CCS and A-S-C-O would increase the proportion of patients with a definitive etiologic mechanism for TIA-MS as compared with TOAST. Methods: Patients were analyzed from the CATCH study. A single-stroke physician assigned all patients to an etiologic subtype using published algorithms for TOAST, CCS and ASCO. We compared the proportions in the various categories for each classification scheme and then the association with stroke progression or recurrence was assessed. Results: TOAST, CCS and A-S-C-O classification schemes were applied in 469 TIA-MS patients. When compared to TOAST both CCS (58.0 vs. 65.3%; p < 0.0001) and ASCO grade 1 or 2 (37.5 vs. 65.3%; p < 0.0001) assigned fewer patients as cause undetermined. CCS had increased assignment of cardioembolism (+3.8%, p = 0.0001) as compared with TOAST. ASCO grade 1 or 2 had increased assignment of cardioembolism (+8.5%, p < 0.0001), large artery atherosclerosis (+14.9%, p < 0.0001) and small artery occlusion (+4.3%, p < 0.0001) as compared with TOAST. Compared with CCS, using ASCO resulted in a 20.5% absolute reduction in patients assigned to the ‘cause undetermined' category (p < 0.0001). Patients who had multiple high-risk etiologies either by CCS or ASCO classification or an ASCO undetermined classification had a higher chance of having a recurrent event. Conclusion: Both CCS and ASCO schemes reduce the proportion of TIA and minor stroke patients classified as ‘cause undetermined.' ASCO resulted in the fewest patients classified as cause undetermined. Stroke recurrence after TIA-MS is highest in patients with multiple high-risk etiologies or cryptogenic stroke classified by ASCO.

Cerebral Hypoperfusion in Posterior Reversible Encephalopathy Syndrome is Different from Transient Ischemic Attack on CT Perfusion.

PRES is a reversible neurotoxic state presenting with headache, altered mental status, visual loss, and seizures. Delayed diagnosis can be avoided if radiological patterns could distinguish PRES from cerebral ischemia. Clinical and radiological data were collected on all hospitalized patients who had (1) discharge diagnosis of PRES and (2) acute CTP/CTA. Data were compared with 10 TIA patients with proven cytotoxic edema on MRI. Of the four PRES patients found, three were correlated with acute blood pressure and one with chemotherapy. At the radiological level, quantitative analyses of the CTP parameters showed that 2 out of 4 patients had bilaterally reduced CBF-values (23.2-47.1 ml/100g/min) in occipital regions, as seen in the pathological regions of TIA patients (27.3 ± 13.5 ml/100g/min). When compared with TIA patients, the pathological ROI's demonstrated decreased CBV-values (3.4-5.6 ml/100g). Vasogenic edema on MRI FLAIR imaging was seen in only one PRES patient, and cytotoxic edema on DWI-imaging was never found. CT angiography showed in one PRES patient a vasospasm-like unilateral posterior cerebral artery. If confirmed by other groups, CTP and CTA imaging in patients with acute visual loss and confusion may help to distinguish PRES from bi-occipital ischemia. These radiological parameters may identify PRES patients at risk for additional tissue infarction.

How predictors and patterns of stroke recurrence after a TIA differ during the first year of follow-up.

The highest risk of subsequent stroke after a TIA occurs within the first week after the index event. However, the risk of stroke recurrence (SR) remains high during the first year of follow-up. We studied the temporal pattern and predictors of SR (at 7 days and from 7 days to 1-year follow-up). Between April 2008 and December 2009, we included 1,255 consecutive TIA patients from 30 Spanish stroke centers (PROMAPA study). We determined the short-term (at 7 days) and long-term (from 8 days to 1 year) risk of SR. Patients who underwent short-term recurrence and long-term recurrence were compared with regard to clinical findings, vascular territories, and etiology. Enough information (clinical variables and extracranial vascular imaging) was assessed in 1,137 (90.6 %) patients. The 7-day stroke risk was 2.6 %. 32 (3.0 %) patients had an SR after 7-day follow-up. Multiple TIA (HR 3.50, 1.67-7.35, p = 0.001) and large artery atherosclerosis (HR 2.51, 1.17-5.37, p = 0.018) were independent predictors of early SR, whereas previous stroke (HR 1.40, 1.03-1.92, p = 0.034) and coronary heart disease (2.65, 1.28-5.50, p = 0.009) were independent predictors of late SR. Notoriously, 80 % of SR happened in the same territory of the index TIA at 7-day follow-up, whereas only 38 % during the long-term follow-up (p < 0.001). Different predictors of SR were identified throughout the follow-up period. Moreover, the ischemic mechanism differed in early and late stroke recurrences.

Abstract T P184: Outpatient Evaluation of Transient Ischemic Attack (TIA) Patients

Objectives: We have started an open-access outpatient TIA Rapid Evaluation Center (TREC) at our community medical center. Patients referred to the TREC are seen on the next weekday and undergo a diagnostic evaluation then consultation with a stroke neurologist. The decision to refer a TIA patient to the TREC is left to the discretion of the attending physician. METHODS: We have collected prospective data from all TREC patients, including follow-up contact at 3 and 12 months to check for future cerebrovascular events. We performed a retrospective chart review on all patients admitted to the hospital with a primary diagnosis of TIA during the same period. This study had IRB approval. RESULTS: We saw 74 TREC patients within an average of 1.25 days of referral during its first year of operation, 56 from the emergency room and 18 from physician offices. Only 2 TREC patients needed admission to the hospital, the remainder completed their evaluation as out-patients. Only 1 TREC patient had a follow-up cerebrovascular event. During this same time period, 88 patients were admitted to the hospital with a primary diagnosis of TIA. Patients referred to the TREC had lower ABCD2 scores (average of 1.8 vs. 3.8, p &lt;0.001) and were less likely to have a final diagnosis of TIA (19% vs. 77% p&lt;0.001) than the hospitalized patients. More hospitalized TIA patients were seen on weekdays than weekends (74% vs. 27%). Nearly all patients underwent CT scan, lipid panel and EKG. However, TREC patients were more likely to undergo carotid ultrasound (99% vs. 84%, p=0.001) and MRI of the brain (89% vs. 68%, p=0.001). Hospital reimbursement from Medicare is $904 for a TREC patient and $5500 for a TIA hospitalization. CONCLUSIONS: 40% of all TIA patients at our hospital were referred to the TREC and seen within 1.25 days during its first year of operation. TIA patients referred to the TREC had lower ABCD2 scores and were less likely to have a final diagnosis of TIA. Day of the week seen did not influence the referral decision. TREC patients were more likely to have a complete diagnostic evaluation at a cost savings of $4600 for Medicare patients. Out-patient evaluation of TIA can be an efficient, safe, and less costly alternative to hospital admission.

Abstract T P193: Impact of Observing TIA Patients in a Clinical Decision Unit

Background: TIA carries a high risk of early stroke. National guidelines recommend that TIA cases should have rapid work up, ideally within 24 hours. Hospitalization is recommended when rapid outpatient work-up is not possible. As a result, most TIA patients are managed in the hospital. However, recent literature supports the use of observation in the Emergency Department for testing and monitoring of TIA patients. Here, we review the effects of our protocol for the observation of TIA cases in a Clinical Decision Unit (CDU) at our Comprehensive Stroke Center (CSC). Methods: Retrospectively, we reviewed the charts of all TIA cases, from one year prior to the use of a CDU protocol, to one year after its use. Patients were identified by billing codes, using our informatics system. Data on location of care, final diagnosis, cost of care, contribution margin, admission rate, and imaging test was collected and analyzed. Descriptive and analytical statistics were used to compare groups. Results: From May 2011 to May 2013, 400 suspected TIA cases were seen. Prior to the initiation of our protocol, 209 TIA patients were hospitalized. After the protocol, 191 patients were seen, with 85 patients seen in the CDU and 106 patients being admitted. The inpatients were mostly cases transferred to our CSC from regional facilities. Of the 85 CDU cases, 51 had a final diagnosis of TIA, 7 had confirmed strokes, 25 were non-cerebrovascular, and 2 were transient global amnesia. From the CDU, 20 patients were admitted, due to confirmation of stroke, recurrence of symptoms, or need for urgent intervention. Over two thirds of all patients underwent MRI/MRA for neuroimaging; the rest had non-contrast CT and carotid ultrasound. Since the start of the TIA protocol, the direct cost of care per case was $453.65 less (p=0.02) in the CDU cases. During the same time period, there was no significant difference in the contribution margin between the CDU and inpatient groups. Conclusion: Given the high risk for early stroke after TIA, early evaluation and monitoring remains imperative. Our results are similar to recent literature, showing that similar management can be provided for less cost and similar clinical outcomes. Larger studies are necessary to determine the overall financial impact of such programs.

Abstract W MP63: Diagnostic Yield of an Extended Ambulatory Cardiac Rhythm Monitor in Patients With TIA or Stroke

Background: In the evaluation of patients with TIA or stroke, the detection of AF changes the recommended anti-thrombotic regimen from treatment with an antiplatelet agent to oral anticoagulation. Detection of supraventricular tachycardia (SVT) may also be relevant as it is associated with an increased risk of AF. This study describes the feasibility and diagnostic yield of the Zio® Patch, a leadless, single-use, small, lightweight, and water-resistant cardiac rhythm monitor that provides continuous cardiac monitoring for up to 14 days. Methods: We obtained de-identified monitoring data from the manufacturer and servicer of the ZioPatch (iRhythm Technologies). Patients who were monitored between January 2012 and June 2013 and whose indication for monitoring, as entered by the ordering provider, was TIA or stroke were included. The duration of monitoring, the number and type of arrhythmias, and the time to first arrhythmia were documented. AF was defined as R-R irregularity for more than 30 seconds in duration. Results: 1,171 monitoring reports were analyzed. The average patient age was 67.9 years. Fifty-five percent of patients were male. The mean monitor wear time was 10.9 days and the median wear time was 13.0 days (interquartile range 7.2-14.0). The median analyzable time relative to the total wear time was 98.7% (IQR 96.0-99.5%). AF was present in 4.8% of all reports (4.2% PAF and 0.6% chronic AF). The mean duration before the first episode of PAF was 1.5 days and the median duration was 0.4 days. 14.3% of first PAF episodes occurred after 48 hours. The mean PAF burden was 12.7% of the total monitoring duration. SVT of 8 beats or more was present in 51% of the records. Conclusion: Virtually the entire duration of monitoring with the ZioPatch yields analyzable data that allows for the detection of cardiac arrhythmias. Among TIA and stroke patients, AF was present in approximately 5% of the records and SVT in 50%. The first episode of PAF frequently occurred more than 48 hours after the start of monitoring. This suggests that Holter (24-48 hour) monitoring is insufficient and supports extended cardiac monitoring in TIA and stroke patients. Further studies are needed to determine which stroke patients are at greatest risk for AF and to assess the clinical significance of SVT.

Abstract T P31: Microembolus (MES) Detection by TCD in Acute Stroke Service

Background and purpose: One of the main applications of TCD in acute stroke is microembolic signal (MES) detection. Both Spectral display and M-mode can be used to detect MES using validated criteria published previously. MES is reported to be an independent risk factor for stroke. Our study’s aim is to evaluate the yield of TCD MES in an acute stroke service and if this correlate with stroke’s mechanism and recurrence of stroke. Methods: We did analysis of all stroke and TIA patients who were evaluated in the University of Alberta Hospital between jan2006- July 2013. The clinical information was collected from charts and TCD studies for MES detection were reviewed by Neurologists certified by American Society of Neuroimaging using validated criteria. All cases had bilateral TCD monitoring of MCA /ACA or PCA vessels. The positive emboli on spectrogram was defined based on the consensus criteria and the M mode one based on our previous published criteria. Positive MES TCD monitoring was defined by the presence of ≥1 MES on either hemisphere. RESULTS: 49 /455 patients(10.7%) were MES positive. Mean age was 54.7(StD ±20), Gender: 33/49( 67.3%)were male, Median duration of monitoring was 50minutes( interquartile range 27.5-60), the indication was TIA in 16/49( 32.7%) acute ischemic stroke in 32/49(65.3%) subarachnoid hemorrhage in 1/49(2%), 36/49( 73.5%) presented with motor weakness 4/49( 8.2%) with isolated vision disturbances, 45/49(91.9%) patients had anterior circulation related symptoms, whereas 4/49(8.2%) had posterior circulation related symptoms,17/49(34.7%) showed acute infarct on imaging 6/49(12.2%) showed both acute and chronic infarcts and 3/49(6.1%) showed chronic infarcts only, 12/49(24.5%) showed infarcts in multiple vessels territories, TOAST: 20/49(40.8%) had large vessel atherosclerosis(LVA), 14/49(28.6%)had cardioembolic(CE) cause, 8/49(16.3%) had other determined etiology and 7/49(14.3%) had cryptogenic stroke, 7/49(14.3%) had recurrent stroke and 1/49(2%) had recurrent TIA. Total no of MES in anterior circulation were 324. CONCLUSION: Our study showed that 1 out of every 10 patients with acute ischemic stroke or TIA showed positive micro embolic signal on TCD monitoring. The high yield was mainly seen in LVA and CE stroke.

Abstract W P285: Communication is the Driver of an Efficient Health Care Team

Background: Comprehensive Stroke Centers provide hyperacute stroke care within hours of symptom onset. Patients benefit from this intervention but still have needs that have yet to be addressed. Health care must be delivered efficiently while meeting the expectations of the public. A methodical solution achieves excellent outcomes for providers, payers, and patients. Purpose: The goal of the health care team is to provide a clear assessment and discharge planning process that enhances communication amongst team members. With an annual volume increase of 10-20%, throughput is a daily challenge at this academic hospital due to rotating physicians and students. Methods: A comprehensive assessment is documented in the electronic medical record within 24 hours of admission by the case management team. This assessment includes screening for depression and need for respite services. A resource guide is immediately provided to the patient and family. Five days a week, the health care team is assembled for “patient care huddles”. These are attended by the vascular neurologist, case management social worker and nurse, speech and physical therapy, stroke program coordinator, pharmacist, utilization review, research coordinator, neurology residents, and each bedside nurse. The 2 minute per patient discussion centers on “plan for the day, plan for the stay”. Results: The number of ischemic stroke and TIA patients has increased 25% over two years. In the same time period, the average length of stay index has decreased from 1.17 to 1.00 and the average cost index is 1.08. Patient satisfaction, as measured by Press Ganey, is at the 98 th percentile for stroke patients over the last two years. Conclusion: Communication among all team members is enhanced through daily patient care huddles and allows discharge planning to start at admission. Comprehensive assessments leading to efficient discharge planning can be achieved without compromising patient satisfaction or increasing costs or length of stay. Throughput is impacted by an efficient, cohesive team.

Abstract 102: Use of Emergency Medical Services by Stroke Patients

Introduction: Rapid evaluation and treatment with rt-PA is the hallmark of acute stroke care, yet only a fraction of ischemic stroke patients arrive within the time window for treatment. National stroke awareness campaigns have attempted to increase community awareness of stroke with action plans to call 911. We sought to compare the use of emergency medical services (EMS) by stroke patients between 2005 and 2010. Methods: Stroke and TIA patients were identified in a population of 1.3 million in the Greater Cincinnati area in 2005 and 2010. Patient charts were abstracted by research nurses and reviewed by study physicians. For this analysis, patients must have resided at home and presented to a local ED. Proportion of EMS users was computed. Logistic regression was used to test for associations of EMS use with age, race, sex, prior stroke, stroke type and severity, and setting (home, work, other) where stroke occurred. Results: There were 2546 stroke cases identified in 2005 and 2704 in 2010 which met criteria for analysis. The mean age was 68 years (SD 15), 54% female, and 20% black in both study periods. EMS use did not change between study periods, 52.7% in 2005 and 52.0% in 2010 (p=.64). In both study years, increasing age, increasing stroke severity, and hemorrhagic stroke were associated with EMS use. History of prior stroke was associated with increased EMS use in 2005, but this association was not seen in 2010. Sex, race, and the setting where stroke occurred were not associated with EMS use. Discussion: Rates of EMS use in our population-based study are still only about 52% and did not increase between 2005 and 2010. Community stroke awareness campaigns should include an action plan containing the urgency of calling 911 as soon as any stroke symptoms occur.

Abstract W P162: Utilization of Vascular Imaging in Stroke: A Population Based Study

Introduction: Rates of diagnostic workup in stroke have increased over time. However less is known about utilization of vascular imaging for stroke from a population perspective. We sought to evaluate the utilization and predictors of vascular imaging modalities in years 2005 and 2010 in a population-based study. Methods: Stroke and TIA patients were identified in a metropolitan population of 1.3 million served by 15 different inpatient hospitals in the Greater Cincinnati area in the calendar years of 2005 and 2010. Patient charts and imaging records were abstracted by research nurses and reviewed by study physicians. The proportion of vascular imaging use including CT angiogram (CTA), MR angiogram (MRA), digital subtraction angiogram (DSA) and carotid ultrasound was computed. Multivariate logistic regression modeling for the following variables was performed: age, race, gender, and insurance, NIHSS, ED presentation and hospital type. Results: In 2005, there were 3558 stroke/TIA events with imaging data available in 3307 patients and, in 2010; there were 3597 stroke/TIA events with imaging data in 3374 patients. Overall, vascular imaging has increased from 72% in 2005 to 77% in 2010 (p-value &lt;0.001). Specifically, use of CTA increased from 2% in 2005 to 11% in 2010 (p-value &lt;0.001), MRA decreased from 38% to 37%, ultrasound increased from 48% to 53% (p &lt;0.001) and DSA decreased from 6% to 3% (p-value &lt;0.001) (table). In the combined study periods, 22% of 7115 events had multiple vascular imaging studies. Younger age, ischemic stroke subtype, ED and academic hospital were associated with increased vascular imaging use. Conclusion: Vascular imaging, particularly noninvasive studies showed increase over time, with CTA studies demonstrating the maximum increase in this population-based study.

Abstract W MP64: Evaluation of Deep Venous Thrombosis in Cryptogenic Stroke and Patent Foramen Ovale

Background and Purpose: In cryptogenic stroke (CS), paradoxical embolus has been suggested as a stroke mechanism. A prior study found a significant rate of pelvic deep venous thrombosis (DVT) using magnetic resonance venography (MRV). We sought to evaluate the yield of diagnostic tests for lower extremity (LE) and pelvic DVT in stroke patients with patent foramen ovale (PFO) and in the subset with CS. Methods: A single center retrospective study was performed to identify consecutive ischemic stroke or TIA patients with PFO who underwent contrast-enhanced 3D pelvic MRV imaging (Ablavar, Lantheus Medical Imaging, N. Billerica, MA) between 2009 and 2013 as part of an inpatient diagnostic evaluation. Results of pelvic MRV, LE Doppler ultrasound (US) as well as clinical data were abstracted. Ischemic subtype was retrospectively assigned using the Causative Classification System (CCS). Patients with possible cardio-aortic embolism and undetermined cause by CCS were classified as CS. We estimated point estimates and 95% confidence intervals (CI) for DVT prevalence among stroke subtypes using the Wald method and compared these using Chi-square tests. Results: Of 130 patients who met study criteria, mean age was 56 +/- 17 years and median time from admission to MRV was 2 days (IQR 1-3). Overall DVT prevalence was 7.7% (95% CI, 4.1 to 13.7); the prevalence of pelvic DVT was 1.6% (95% CI, 0.07 to 5.8) and that of LE DVT was 7.2% (95% CI, 3.7 to 13.3). Of the patients with pelvic DVT (n=2), one patient also had a LE DVT by US. When MRV or US was obtained within 72 hours following admission, the prevalence of pelvic DVT was 2.1% (95% CI, 0.12 to 7.7) and that of LE DVT was 7.8% (95% CI, 3.8 to 14.8). Comparing patients with CS (n=97) to other subtypes (n=33), there was no difference in the prevalence of pelvic DVT (2.1% vs. 0%, P=1), LE DVT (6.3% vs. 10.3%, P=0.43) or any DVT (7.2% vs. 9.1%, P=0.71). Conclusion: Patients with CS and PFO have similar prevalence of DVTs compared to other stroke subtypes. The majority of detected DVTs were in LE veins rather than pelvic veins. Only a single patient with a pelvic DVT did not have a coexistent LE DVT. Our results suggest that the utility of pelvic MRV may be much lower than previously reported.

Abstract W P175: Diagnostic Yield of Echocardiography in Patients Presenting with Transient Ischemic Attack

Background: Transthoracic (TTE) or transesophageal (TEE) echocardiography is often performed to identify a cardioembolic (CE) source as part of the TIA evaluation. However, TTE/TEE can be difficult to obtain on an urgent basis, and the diagnostic yield in TIA remains undetermined. Methods: Patients with presumed TIA (defined as acute onset of focal symptoms lasting &lt;24 hours likely due to a vascular cause) within 48 hours after presentation were prospectively enrolled at 3 stroke centers. Data regarding clinical features, medical history, results of diagnostic testing including TTE/TEE, treatment at discharge, and 90-day outcome were recorded. TIA etiology was determined by the enrolling investigator from all available information. CE sources were defined using a modified version of the Causative Classification of Stroke system. Results: A total of 633 TIA patients were included. Mean age was 66 ± 15 years, 52% were male, and the median ABCD 2 score was 4 (IQR 3-5). The 90 day stroke rate was 2% (12/633). TIA mechanism was determined to be CE in 16% of subjects. Echocardiography was performed in 495 subjects (TTE alone in 444, TTE+TEE in 44, and TEE alone in 7). TTE revealed a CE source in 45/488 (9%) patients. TEE revealed a CE source in 17/51 (33%) patients, of whom 9 had either negative TTE or TTE was not performed. Therefore, the overall yield of TTE/TEE for a CE source was 54/495 (11%). The most common CE source detected on TTE/TEE was dilated cardiomyopathy; CE sources not detected on TTE/TEE consisted mostly of atrial fibrillation. Anticoagulation was initiated because of a CE source found on TTE/TEE in 19/495 (4%) patients. Of those who underwent an MRI, 169/495 (34%) were DWI+. Yield of both TTE and TEE tended to be higher in DWI+ compared to DWI- subjects (TTE: 17/146 [12%] vs 17/235 [7%], p=0.14; TEE: 12/27 [44%] vs. 1/15 [7%], p=0.01). Conclusions: TTE and TEE identify a CE source and prompt a change in antithrombotic regimen with sufficient frequency to consider their inclusion in the diagnostic evaluation of patients with TIA. The yield of these tests, particularly TEE, is higher in patients with diffusion restriction on MRI.